State Of The Air: Report Reveals America's Most Polluted (And Cleanest) Cities

America's air quality is improving, despite more than 40 percent of Americans living in areas where pollution levels make breathing the air potentially dangerous, and Los Angeles remains the city with the worst ozone pollution problems, according to the 2013 State of the Air report released Wednesday. Most of the country's top polluted cities are in California.

More than 131.8 million people in the United States, which equates to 42 percent of the U.S. population, live in counties that have unhealthy levels of either ozone or particle pollution, the report stated.

The report, published by the American Lung Association, did say that overall, air quality in America has continued to improve since the implementation of the Clean Air Act in 1970, but many cities that ranked among the most polluted had more unhealthy days of high ozone (smog) and short-term particle pollution than in the 2012 report.

The report examined ozone levels and the air's particle pollution (soot) into short-term (24-hour exposure) and annual pollution. Nearly 25 million people (8 percent of the U.S. population) live in triple threat counties that have unhealthy levels of ozone, short-term and year-round particle pollution.

But 18 cities had lower year-round levels of particle pollution, including 16 cities with their lowest levels recorded, the report states. More cities - four - made the list of the "cleanest cities" than in any previous "State of the Air" report: Bismarck, N.D.; Cape Coral-Fort Myers, Fla.; Palm Bay-Melbourne-Titusville, Fla.; and Rapid City, S.D. To make this list, the cities had to have no days with unhealthy levels of ozone or particle pollution and had to be among the 25 cities with the lowest year-round particle levels.

"We are happy to report that the state of our air is much cleaner today than when we started the 'State of the Air' report 14 years ago," said Harold Wimmer, National President and CEO of the American Lung Association, in a press statement. "Even in parts of the country that experienced increases in unhealthy days of high ozone and short-term particle pollution, they still have better air quality compared to a decade ago. But the work is not done, and the Environmental Protection Agency must continue the work necessary to achieve the promise of the Clean Air Act; healthy air that is safe for all to breathe."

According to Huffington Post, earlier this month, the director general of the U.N. Industrial Development Organization told a conference, "Air pollution is causing more deaths than HIV or malaria combined."

The State of the Air report corroborates, saying both ozone and particle pollution can cause early death.

The complete 2013 State of the Air report can be viewed here.